locale/gen-translit.py

   1 #!/usr/bin/python3
   2 # Generate the locale/C-translit.h file.
   3 # Copyright (C) 2018-2022 Free Software Foundation, Inc.
   4 # This file is part of the GNU C Library.
   5 #
   6 # The GNU C Library is free software; you can redistribute it and/or
   7 # modify it under the terms of the GNU Lesser General Public
   8 # License as published by the Free Software Foundation; either
   9 # version 2.1 of the License, or (at your option) any later version.
  10 #
  11 # The GNU C Library is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 # Lesser General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU Lesser General Public
  17 # License along with the GNU C Library; if not, see
  18 # <https://www.gnu.org/licenses/>.
  19
  20 import re
  21 import sys
  22
  23
  24 class StringLiteral:
  25     "Source of a string literal and its decomposition into code points."
  26     def __init__(self, s):
  27         # States:
  28         #  0 regular character sequence
  29         #  1 backslash seen
  30         #  2 in hexadecimal escape sequence
  31         state = 0
  32         result = []
  33         for ch in s:
  34             if state == 0:
  35                 if ch == '\\':
  36                     state = 1
  37                 else:
  38                     result.append(ord(ch))
  39             elif state == 1:
  40                 if ch in "\\\"":
  41                     result.append(ord(ch))
  42                     state = 0
  43                 elif ch == 'x':
  44                     state = 2
  45                     result.append(0)
  46                 else:
  47                     raise ValueError("invalid character {!r} in {!r}".format(
  48                         ch, s))
  49             elif state == 2:
  50                 if ch in "0123456789abcdefABCDEF":
  51                     result[-1] = result[-1] * 16 + int(ch, 16)
  52                 else:
  53                     if ch == '\\':
  54                         state = 1
  55                     else:
  56                         state = 0
  57         if state == 1:
  58             raise ValueError("trailing backslash in {!r}".format(s))
  59
  60         self.source = s
  61         self.decoded = tuple(result)
  62
  63
  64 class Translit:
  65     "Pair of transliteration and source."
  66
  67     __RE_TRANSLIT = re.compile(
  68         r'^"((?:[^"\\]|\\x[0-9a-fA-F])+)"\s+'
  69         r'"((?:[^"\\]|\\["\\])*)"\s*(?:#.*)?$')
  70
  71     def __init__(self, line):
  72         match = self.__RE_TRANSLIT.match(line)
  73         if not match:
  74             raise IOError("invalid line {}: {!r}".format(
  75                 lineno + 1, line))
  76         codepoints, replacement = match.groups()
  77         self.codepoints = StringLiteral(codepoints)
  78         self.replacement = StringLiteral(replacement)
  79
  80
  81 # List of Translit objects.
  82 translits = []
  83
  84 # Read transliterations from standard input.
  85 for lineno, line in enumerate(sys.stdin):
  86     line = line.strip()
  87     # Skip empty lines and comments.
  88     if (not line) or line[0] == '#':
  89         continue
  90     translit = Translit(line)
  91     # Check ordering of codepoints.
  92     if translits \
  93        and translit.codepoints.decoded <= translits[-1].codepoints.decoded:
  94         raise IOError("unexpected codepoint {!r} on line {}: {!r}".format(
  95             translit.codepoints.decoded, lineno + 1, line))
  96     translits.append(translit)
  97
  98 # Generate the C sources.
  99 write = sys.stdout.write
 100 write("#include <stdint.h>\n")
 101 write("#define NTRANSLIT {}\n".format(len(translits)))
 102
 103 write("static const uint32_t translit_from_idx[] =\n{\n  ")
 104 col = 2
 105 total = 0
 106 for translit in translits:
 107     if total > 0:
 108         if col + 7 >= 79:
 109             write(",\n  ")
 110             col = 2
 111         else:
 112             write(", ")
 113             col += 2
 114     write("{:4}".format(total))
 115     total += len(translit.codepoints.decoded) + 1
 116     col += 4
 117 write("\n};\n")
 118
 119 write("static const wchar_t translit_from_tbl[] =\n ")
 120 col = 1
 121 first = True
 122 for translit in translits:
 123     if first:
 124         first = False
 125     else:
 126         if col + 6 >= 79:
 127             write("\n ")
 128             col = 1
 129         write(" L\"\\0\"")
 130         col += 6
 131     if col > 2 and col + len(translit.codepoints.source) + 4 >= 79:
 132         write("\n  ")
 133         col = 2
 134     else:
 135         write(" ")
 136         col += 1
 137     write("L\"{}\"".format(translit.codepoints.source))
 138     col += len(translit.codepoints.source) + 3
 139 write(";\n")
 140
 141 write("static const uint32_t translit_to_idx[] =\n{\n  ")
 142 col = 2
 143 total = 0
 144 for translit in translits:
 145     if total > 0:
 146         if col + 7 >= 79:
 147             write(",\n  ")
 148             col = 2
 149         else:
 150             write(", ")
 151             col += 2
 152     write("{:4}".format(total))
 153     total += len(translit.replacement.decoded) + 2
 154     col += 4
 155 write("\n};\n")
 156
 157 write("static const wchar_t translit_to_tbl[] =\n ")
 158 col = 1
 159 first = True
 160 for translit in translits:
 161     if first:
 162         first = False
 163     else:
 164         if col + 6 >= 79:
 165             write("\n ")
 166             col = 1
 167         write(" L\"\\0\"")
 168         col += 6
 169     if col > 2 and col + len(translit.replacement.source) + 6 >= 79:
 170         write("\n  ")
 171         col = 2
 172     else:
 173         write(" ")
 174         col += 1
 175     write("L\"{}\\0\"".format(translit.replacement.source))
 176     col += len(translit.replacement.source) + 5
 177 write(";\n")